The invention relates to a heatable media line.
Heated media lines in the vehicle sector often involve diesel exhaust fluied (e.g., AdBlue®) lines, lines for windshield washer fluid, headlamp washer fluid, process media of a fuel cell, etc., i.e., lines intended for carrying a medium, in which freezing must be prevented with an eye toward internal combustion engine operation and driving comfort. However, the urea solution used in tanks as a fuel additive and known by the name AdBlue® freezes at −11° C., and thus must always be heated during winter operation. In order to ensure flawless vehicle operation under all expected operating temperatures, the tanks, lines and other components carrying the respective medium at risk of freezing must be heated.
Known from DE 10 2014 004 134 A1 is a heatable media line for a vehicle, which consists of an upper part and a cylindrical lower part that acts as a coupling piece and establishes a connection between the opposing ends of two media lines. There are welded connections between the upper part and lower part, as well as between the lower part and media lines. The upper part is provided with two passages that each incorporate a connecting cable, wherein the electrical attachment points designed as crimping connections sealed by a melt adhesive between the connecting cables and the heat conductors extending inside the media lines and into the filler body are accommodated inside of the upper part otherwise filled with a filler body made out of a plastic. The heat conductors are centrally guided inside of the media lines in the form of a closed loop, so that given a uniform all-around heating, the flow of a medium in the lines is not impaired. The heat conductors are tightly introduced into the upper part by means of packing washers and upper side end caps spaced apart therefrom, which leave an uncovered, free region.
It has been determined that a urea solution in the form of the mentioned AdBlue® medium, which involves an aqueous solution of highly pure urea in demineralized water, is especially able to creep due to its low viscosity, so that special measures are required to establish a reliable seal, in order to prevent this extremely corrosively acting medium from undesirably spreading. In particular, penetration into parts of an electrical connection must be prevented with an eye toward avoiding electrical short circuits.